Antioch fire officials are crediting a quick-thinking boy for alerting them in time to a family of four found unconscious in their home from carbon monoxide poisoning this morning.

The boy had gone to the home in the 1100 block of Bowles Road where his girlfriend lived with her sister and parents around 5:55 a.m. but got no answer at the door, said Antioch Fire Chief John Nixon. He looked through the living room window and saw his girlfriend's father passed out and called 911, Nixon said.

"He said no one was answering the door and he couldn't get in and he called in and said he could see a person laying down in the living room," Nixon said. "If it wasn't for this young man, I'm pretty sure we'd have a much worse outcome.

"He is (a hero), he had a lot to do with a good outcome so far."

Paramedics broke through the door and also found a person unconscious on the first floor, while firefighters found two other people unconscious in their beds. The family dog was also passed out, Nixon said.

All of the people in the home and the dog were revived, Nixon said. "They evacuated the patients from the house," he said, adding that the residents were taken in serious condition to hospitals.

The victims were out of the house and being treated by paramedics 16 minutes from the time the boy called, according to Nixon.

One of the adults and a child were taken to St. Catherine's Hospital in Kenosha and the other two were taken to Aurora Medical Center in Kenosha County, he said. The dog was given oxygen and taken to an animal hospital, Nixon said.

The readings of carbon monoxide were in the "high level," around 600 parts per million, which could be fatal, he said. Officials said they could not find any carbon monoxide detectors in the home.

Nixon said the cause of the poisoning is under investigation, but officials suspect a malfunctioning boiler.